using System;

using System.Linq;

using System.Security.Cryptography;

public class Program

{

    // Example:

    // 01000000000008719115|9209182741104

    //So you need to put to data this part:

    // 01000000000008719115|9209 (i.e. the whole part before calculated check digit)

    private const int LEN = 9;

​

    private const byte MASK = 0xFD;

    public static void Main()

    {

        string data = "01000000000008719115|9209"; // <-- HERE

        string dataRplc = data.Substring(0, data.IndexOf("|"));

        byte[] arr = new byte[dataRplc.Length * sizeof(char)];

            Buffer.BlockCopy(dataRplc.ToCharArray(), 0, arr, 0, arr.Length);

​

        for (int i = 0; i < arr.Length; i++)

            arr[i] &= MASK;

​

        string res;

        using (SHA1 crypto = SHA1.Create())

            res = string

                .Concat(crypto.ComputeHash(arr).Select(x => x.ToString()))

                .Substring(0, LEN);

        Console.WriteLine(data + res);

    }

}